Building blocks made of concrete or cementaceous material are widely used for building structures. Typically, these blocks are laid in running courses with horizontal and vertical mortar joints, known as butt joints and head joints, to construct a wall. The mortar bonds the block material together to form the completed wall construction. Conventional cement block wall construction employs blocks which are closed at the ends by cross webs, and which typically include a single cross web substantially at the midpoint of the block. The open spaces between the cross webs are used to provide air spaces for insulation purposes and to reduce the weight of the block. These open spaces also are used to accommodate reinforcing bar placement and grout cells for providing a structurally reinforced wall.
Efforts have been made to improve the insulation qualities of concrete block walls by filling the voids between the supporting cross webs with molded insulating material during manufacture of the block. When such cells are prefilled, however, and the block is stored in an outdoor storage yard pending shipment, the insulating material frequently deteriorates in reaction to ultraviolet rays and the like. In addition, when the hollow cells in a masonry block are pre-filled at manufacture, the block is difficult to handle, because of an inadequate means of picking up the block. The foam fills the cores preventing a mason from efficiently grasping the central web or the end web of the block and placing it, a process that is repeated for each and every block during construction. Masons generally prefer a block which can be handled with one hand; so that the other hand can be free to hold a trowel, some other tool, or carry another block.
Composite insulated building block structures have been devised for two-stage construction. First, the blocks are laid using conventional block and mortar structure, but where the blocks have some open overlapping cells. Then a second step involves the subsequent insertion of insulating cores into the voids between the cross webs of the block. The U.S. patent to Perreton U.S. Pat. No. 3,204,381 discloses such a structure. The insulation inserts of Perreton, however, are designed to extend above the upper surface of the blocks for the purpose of establishing a mortar space between adjacent courses. Also, there is no provision for accommodating mortar weepage, which occurs during the construction of a wall using the blocks. As a result, insertion of the insulation inserts may damage or destroy the integrity of the mortar, resulting in an unacceptable construction.
Another patent using insulation inserts in an otherwise conventional block structure is the U.S. patent to Jensen U.S. Pat. No. 4,193,241. Inserts in the Jensen system are placed in the hollow spaces between the webs of the block. These inserts are designed to extend above the upper surface of the block for the purpose of establishing a mortar space between adjacent courses. A problem which exists in both the Perreton and Jensen patents, using inserts which extend above the upper surface of the block itself, is that the inserts interfere with the application of and adjustability of the mortar joint between adjacent courses of blocks. They also require the mason to employ techniques in applying the mortar which differ from those which normally are used with standard concrete blocks not employing such inserts.
The U.S. patent to Johnson U.S. Pat. No. 4,748,782 discloses a variation of the Perreton block which employs overlapping open cells designed for use with insulating foam inserts to provide a self-aligning, self-leveling drystacking (without mortar) construction. Since no mortar is employed in the block configurations of a wall built in conjunction with the blocks of the Johnson patent No. U.S. Pat. No. 4,748,782, uniform and accurate block sizing is critically important. Concrete masonry blocks currently are manufactured almost exclusively by automated heavy equipment, which rapidly produces the blocks. Because the concrete and aggregate employed in molding such blocks are highly abrasive, the precisely engineered, high stress metal molds rapidly wear. This causes the dimension of the block produced by the molds to vary as the mold ages. The blocks grow in length and thickness; and the core cells increase in size. As a result, the maintenance of a constant height becomes increasingly more difficult the longer the mold is employed in manufacturing.
In the drystack block configuration of the Johnson patent U.S. Pat. No. 4,478,782, the molded inserts include recesses and projections which extend from one course to the next to facilitate the precise alignment of the block wall. In order to complete a wall construction using the blocks of the Johnson patent, surface bonding is applied to the wall after the blocks have been stacked in place. The surface bonding then provides a strong integral wall. Surface bonding, however, precludes the use of split face block construction or any block construction which does not utilize a separate or subsequent finish after the wall has been constructed. Split block construction, however, is widely used, particularly in the construction of commercial buildings; so that this is a drawback to universal use of the block construction disclosed in the Johnson patent U.S. Pat. No. 4,748,782.
Concrete blocks also are somewhat difficult to handle. Conventional blocks generally are picked up by a mason by pinching the thumb and four fingers together at the center web and lifting the block using primarily the smaller forearm muscle. Since the blocks weigh approximately thirty-two pounds each, a significant muscular strain is caused by repetitive handling of the blocks.
Two patents which are directed to efforts at improving the handling characteristics of concrete blocks are the U.S. patents to Stevens U.S. Pat. No. 5,421,135 and Munsey U.S. Pat. No. 5,787,670. The Stevens patent is directed to a drystack block; and the central web is relieved from the bottom to provide a convenient handle for placing the block. The handle is oriented transversely of the longitudinal dimension of the block.
The patent to Munsey U.S. Pat. No. 5,787,670 is directed to a generally conventional building block which has an integral handhold constructed into a center transverse web. Because of the location of the opening for the handle and the configuration of the handle, this block is relatively difficult to manufacture. The block first is molded in a conventional manner. Then, while the block is still xe2x80x9cwetxe2x80x9d, the handle opening is punched out prior to kiln drying of the block. As a consequence, the block is not particularly practical to manufacture because of the extra step required to produce it.
It is desirable to provide an improved insulated masonry building block which overcomes the disadvantages of the prior art, and which employs generally conventional masonry techniques in wall construction using the block coupled with effective insulation and ease of handling.
It is an object of this invention to provide an improved insulated masonry building block.
It is an additional object of this invention to provide an insulated masonry building block utilizing insulating foam inserts to increase overall thermal performance of the wall using such blocks, without interfering with butt or head mortar joints. It is another object of this invention to provide a masonry building block construction which facilitates ease of handling the block by the mason.
It is a further object of this invention to provide an improved insulated masonry building block capable of installation in accordance with standard masonry practices, in which non-mortar interfering insulation inserts are inserted after a course is laid and are non-mortar interfering, and which permits installation of electrical boxes and interconnecting conduit securely within the block cavities.
In accordance with a preferred embodiment of the invention, an insulated masonry building block is constructed with first, second and third spaced parallel rectangular side walls, in which the second side wall is intermediate the first and third side walls. First and second vertical end cross webs then connect the first and second side walls; and each of the first and second end cross webs have a notch in them extending a predetermined distance from the top toward the bottom. First and second spaced intermediate vertical cross webs then are located on planes between the planes of the first and second end webs to connect the second and third side walls, leaving open cavities at the ends of the second and third side walls. Each of these intermediate cross webs also have a notch therein extending from the top a predetermined distance toward the bottom.
A first insulating core is dimensioned to substantially fill the space between the first and second side walls and the first and second end cross webs; and this core has protrusions extending outwardly near the top thereof to fit into the notches in the first and second end cross webs. The first insulating core also has a longitudinal notch along the bottom thereof to eliminate mortar interference when it is inserted into a block which has been laid previously in a course during building construction.
An additional embodiment includes a second insulating core dimensioned substantially to fill the space between the first and second spaced intermediate cross webs. This second insulating core has protrusions extending outwardly from the top thereof on each side to fit into the notches in the intermediate cross webs, and also includes a vertical notch extending from the top to the bottom thereof at substantially the midpoint, along with a longitudinal notch along the bottom edge thereof. The second core also is used to fill the cavity between adjacent blocks after they are laid in a course; and the vertical notch permits non-mortar interfering insertion of the core when it bridges between adjacent blocks.